Fluid pressure control mechanism



Nov. 13, 1934. x H. C..FRENTZEL, JR 1,980,478

FLUI D PRESSURE CONTROL MECHANISM Filed'March 19, 195].

IN VEN TOR.

Patented Nov. 13, 1934 UNITED STATES FLUID PRESSURE CONTROL MECHANISMHerman C. Frentzel, Jr., Milwaukee, Wis., as-

signor, by mesne assignments, to The Heil 00., Milwaukee, Wis., acorporation of Wisconsin Application March 19, 1931, Serial No. 523,703

3 Claims.

The present invention relates in general to improvements in the art offluid distribution, and relates more specifically to improvements in theconstruction and operation of mecha- 5 nisms for controlling thedelivery of fluid from orifices or the like.

An object of the invention is to provide improved fluid pressure controlmechanism which is simple in'construction and efficient in operation.

In the art of utilizing combustible fluid such as oil, for heatingpurposes, it is not only desirable to be able to accurately control thequantity of oil normally delivered to the combustion chamber from thesupply nozzle, but it is furthermore highly desirable to have the oilsupply automatically stopped under certain conditions of operation, inorder to avoid flooding of the combustion chamber with explosive liquidin case the flame is extinguished. The quantity control shouldpreferably be adjustable to meet various conditions of operation, andthe delivery of fluid from the nozzle should be substantially constantfor a predetermined position of adjustment of the quantity controlmeans. Regardless of the position of adjustment of the quantity controlmeans, it is desirable to have the fuel supply pump operable atsubstantially constant speed so that the delivery of fuel therefrom willbe substantially constant at all times. It has heretofore beenimpossible with the prior control mechanisms for oil burners and thelike, to accurately control the delivery of fuel from the supply nozzlewith the pump operating at substantially constant speed, due to thecomplexity of the prior control devices and also due to the lack offlexibility in the adjustment thereof.

It is a more specific object of the present invention to provide simpleand compact control mechanism which is especially adapted for use inconjunction with oil burner nozzles or the like, for the purpose ofaccurately regulating the delivery of fuel to the combustion zone.

Another specific object of the invention'is to provide an improvedcontrol device for oil burners or the like wherein the fuel supply tothe discharge nozzle will be automatically stopped when certain abnormalconditions of operation are attained.

A further specific object of the invention is to provide a fuel supplyregulator for burners, which is highly flexible and extremely accuratein operation, and which may be maintained in highly effective conditionat all times.

Another specific object of the invention is to provide a fuel flowcontrol which will function effectively without in any manner disturbingthe operation of the fuel supply pump, and in which the pump may bemaintained in operation at full capacity even when the delivery of fluidto the combustion zone is stopped.

Still another specific object of the invention is to provide a fuelregulator device which may be manufactured and installed at minimumcost.

These and other objects and advantages will be apparent from thefollowing detailed description.-

A clear conception of an embodiment of the invention and of the modeof'constructing and of operating devices built in accordance therewith,may be had by referring to the drawing accompanying and forming a partof this specification in which like reference characters designate thesame or similar parts in the several views.

Fig. 1 is a central vertical section through a fluid pressure controlmechanism especially adapted for oil burner service, showing the variousparts in inactive position;

Fig. 2 is a transverse vertical section through the mechanism of Fig. 1,the section having been taken along the line 2-2 of Fig. 1 looking inthe direction of the arrows; and

Fig. 3 is a diagram showing the relative disposition of the controlmechanism and of the pump for supplying fluid under pressure thereto.

While the invention has been shown and described herein as beingspecifically adapted for use in connection with, and as actually appliedto an oil burner unit, it will be apparent that the improvement is moregenerally applicable to fluid pressure regulating or control mechanisms.This illustrative disclosure should not therefore be considered as anintentional limitation in the scope of the present invention. It shouldalso be understood that the improved mechanism is capable of operatingto control the delivery of fluids other than oil, without departing fromthe realm of the present invention.

Referring to the drawing, the improved control mechanism comprises ingeneral a main casing 4 forming a chamber 5 having a supply passage 6communicating therewith. The casing 4 is additionally provided with afluid discharge orifice 7 and with a by-pass 8, both of which arecommunicable with the chamber 5 under certain conditions of operation.In addition to the discharge port and by-pass, the casing 4 is alsoprovided with parallel bores 9, 10 in the former of which a plunger 11is movable and in the latter of which a second plunger 12 is similarlymovable.

The bore 9 is disposed substantially in line with the discharge orifice'7, and the primary plunger 11 carries a needle valve 13 whichcooperates with the orifice '7 to control the delivery of fluid from thechamber 5 to the nozzle 14. The needle valve 13 is movably supported inan end socket in the plunger 11, by means of a transverse pin 15 so thatthe cone point of the valve 13 may find a proper seating upon the casing4 at the orifice '7, even if the needle valve and orifice are notperfectly alined. The plunger 11 is constantly urged toward the chamber5, by means of a helical compression spring ,16 which reacts against aremovable plug 17 secured to the casing 4, and the chamber within whichthe spring 16 is confined, communicates with the by-pass 8 through aport 18, thereby subjecting the end of the plunger 11 remote from thechamber 5 to by-pass pressure at all times. The range of movement of theprimary plunger 11 may be predetermined by an adjustable stop member 19having screw thread coaction with the plug 17 and extending centrallythrough the spring 16 in proximity to the end of the plunger 11. Thestem of the stop member 19 extends through the plug 17 and is providedwith a hand wheel 20 for permitting adjustment of the stop, and asuitable packing 22 serves to prevent escape of oil from within thecasing 4 along the stem of the member 19. By manipulating the hand wheel20, the stop member 19 may be set to establish any desired range oftravel of the needle valve 13, and to positively close this valve if sodesired.

The bore 10 within which the second plunger 12 is movable, may be of thesame diameter as the bore 9 in order to facilitate machining of theparts, and the opposite ends of the secondarybore 10 are in opencommunication with the chamber 5 and by-pass 8, respectively. The secondplunger 12 is hollow and the internal space 23 is provided with radialinlet and discharge ports 24, 25 respectively, which under certainconditions of operation are adapted to communicate respectively with thechamber 5 and with the by-pass 8 adjacent the corresponding ends of thebore 10. The end of the plunger 12 within the chamber 5, is providedwith a cap 26 which is engageable with an abutment 27 on the casing 4 tolimit the'movement of the plunger in one direction. The secondaryplunger 12 is constantly urged toward the abutment 27, by means of ahelical compression spring 28 which reacts against .a plate 29. Anelongated pin 30, threaded into the member 10, facilitates thewithdrawing of the spring 28 and the plunger 12. The outer portion ofthe casing 4 in line with the bore 10, is provided with a removableclosure plug 31 having a central threaded opening the screw threads ofwhich coact with a hollow adjusting screw 32 which loosely embraces theadjacent end of the rod 30 and coacts with the plate 29. The outer endof the screw 32 is provided with a slot for efiecting adjustment of thescrew and of the plate 29 so as to vary the tension of the spring 28. Aclamping nut 33 serves to lock the afforded by the spring 28 mayobviously be readily varied as desired, by merely manipulating the'screw 32.

The by-pass 8 may be connected directly to a supply tank 35 as showndiagrammatically in Fig. 3, and a pump 36 of any suitable constructionmay have its suction line 37 connected to this same tank. The pump 36 ispreferably operated to produce uniform and substantially constantdisplacement, and has its discharge connected directly to the supplypassage 6 of the casing 4. The casing 4 may be attached to a nozzlesupport 38 which provides a housing for a strainer 39 so disposed thatthe oil delivered from the orifice 7 must pass through the strainerbefore reaching the nozzle 14. The strainer 39 is readily removable fromthe support 38 for inspection and cleaning, by removal of the strainerretainer 40, and the nozzle 14 is also removable from the support 38 forlike purposes.

During normal operation of the improved control device, the pump 36 isoperating to deliver fluid under pressure to the chamber 5 at asubstantially constant rate. The hand wheel 20 is normally adjusted topermit opening of the needle valve 13 and the hand wheel is turned backas far as possible with the stop portion 19 engaging the inner end ofthe member 17 and being prevented from withdrawal. The tension of thespring 28 has been adjusted by manipulation of the screw 32 to permitopening of the by-pass only upon attainment of a predetermined pressurewithin the chamber 5, the by-pass will be thus opened upon attainment ofsaid pressure and the primary plunger 11 will be automatically forcedback to open the needle valve 13 thereby causing delivery of fluid underpressure from the chamber 5 to the nozzle 14. By varying the tension ofthe spring 28 which coacts with the secondary plunger 12, the pressurewithin the chamber 5 may be adjusted toany desired point and will bemaintained substantially constant for the predetermined setting. If thepressure in the chamber 5 tends to drop by virtue of a reduction in thesupply of fluid, the by-pass plunger 12 will move toward the chamber 5and will eventually cut oil the ports 24, 25, thereby preventingbypassing of fluid and permitting the valve 13 to stantially constantpressure within the chamber 5 and will thus maintain a substantiallyconstant rate of delivery of fluid under the predetermined pressure, tothe nozzle 14.

The secondary plunger 12 by virtue of its formation, operates with greatsensitiveness, The ports 24 are disposed oppositely with respect to eachother and thereby prevent the escaping fluid from undesirably tiltingthe plunger 12 within the bore 10. The end cap 26 provides the pressuresurface against which the fluid acts, and the discharge ports 25likewise prevent tilting of the plunger 12 due to unbalanced lateralpressures on the plunger. Adjustment of the tension of the spring 25 maybe readily effected by removal of the closure cap 34 and subsequentmanipulation of the adjusting screw 32, and the nut 33 serves topositively lock the screw 32 in any desired position of adjustment.

The mounting of the needle valve 13 obviously permits tight closing ofthe valve with respect to the orifice 7, and the range of movement ofthe valve 13 may be conveniently adjusted by means of the hand wheel 20.If the range of movement of the valve 13 is great, then the spring 16will be placed under greater tension as the valve 13 opens farther. Thetension of the spring 16, may also be varied by inserting shims ofdifferent thickness between the plug 17 and the easing 4, if so desired,and the valve 13 may be positively closed with the aid of the hand wheel20 and stop member 19, if so desired. Such closingof the needle valve 13does not affect the operation of the supply pump 36, since the by-passplunger 12 will then permit by-passing of the entire quantity of fluidwhich is delivered to the chamber 5 from the pump.

If for any reason the pressure within the chamber'B should fail, theplunger 11 will be forced forwardly by its spring 16 to close the needlevalve 13, and the plunger 12 will likewise be forced forwardly againstthe abutment 27' by means of its spring 28. The bores 9, 10 may be ofequal diameter as shown, or these bores may be of different diameters.The equal diameter bores may be more readily machined, and so far aspossible, all parts of the mechanism are made interchangeable therebyreducing to a minimum the cost of construction..

From the foregoing description it will be apparent that the inventionprovides a simple and compact control mechanism adapted to accuratelyregulate the delivery-of liquid from a chamber. The device has beenfound especially effective when used in conjunction with oil burnernozzles, since the supply of fluid to the nozzle is automaticallyand-quickly stopped when abnormal conditions of operation are attained.The desired adjustments may be quickly and accurately accomplished andthe operation of the fuel supply pump need not be disturbed when a newadjustment is made.

It should be understood that itis not desired to limit the invention tothe exact details of construction and to the precise mode of operationherein shown and described, for various modifications within the scopeof the claims may occur to persons skilled in the art.

It is claimed and desired to secure by Letters Patent: 1

1., In combination, a casing forming a chamber having a pair of bores ofuniform cross-section communicating therewith throughout the fullcross-section of both bores, a plunger slidable along each of saidbores, a fluid intake communicating with said chamber to subject saidplungers to pressure over the entire crosssectional areas thereof,resilient means for urging said plungers toward said chamber inopposition to the fluid pressure therein, a fluid outlet communicatingwith said chamber, a valve carried by one of said plungersforcontrolling the delivery of fluid through said outlet, and a fluidpressure relief passage communicating directly with both of said boresremote from said chamber, the other of said plungers having an endportion movable into said chamber and pro-. vided with lateral portsexposed to said passage and to said chamber respectively only when saidportion enters said chamber for permitting escape of fluid from saidchamber through said other plunger to said relief passage.

2. In combination. a casing forming a chamber having a pair of bores ofuniform crosssection communicating therewith throughout the fullcross-section of both bores, a plunger slidable along each of saidbores, a fluid intake communicating with said chamber between said boresto subject said plungers to pressure over the said chamber and providedwith lateral ports exposed to said passage and to said chamberrespectively only when said portion enters said chamber for permittingescape of fluidfrom said chamber through said other plunger to saidrelief passage.

3. In combination, a casing forming a chamber having parallel borescommunicating therewith and extending to the exterior of the casing, aplunger slidable within each of said bores adjacent said chamber, afluid intake communicating directly with said chamber, a fluid outletcommunicating with said chamber in line with one of said plungers, avalve carried by said plunger for controlling the delivery of fluid fromsaid chamber through said outlet, a spring for urging said plunger andsaid valve toward said outlet, a stop adjustable from the exterior ofsaid casing and. coacting directly with said plunger within said springfor controlling the degree of opening of said valve, a fluid pressurerelief passage communicating directly with both of said bores remotefrom said chamber, a spring for urging the other of said plungers towardsaid chamber and away from said relief passage, and means for varyingthe tension of said last- 'mentioned spring from the exterior of saidcasing, said other plunger having ports for controlling the flow offluid from said chamber through said plunger to said relief passage.

HERMAN C. FRENTZEL, Ja.

